Sheet discharge device, and image forming system

Abstract

A sheet discharge apparatus includes a first tray for stacking sheets, and a sheet bundle forming unit that forms a sheet bundle on the first tray. The sheet bundle forming unit forms a first sheet bundle on the first tray, and forms a second sheet bundle on the first sheet bundle to be offset from the first sheet bundle. When forming each of the first sheet bundle and the second sheet bundle on the first tray, the sheet bundle forming unit divides sheets constituting each of the sheet bundles into a plurality of sets and discharges the sheets in a plurality of times for each sheet bundle. A number of sheets included in a first sheet set of the first sheet bundle is set smaller than a number of sheets included in a first sheet set of the second sheet bundle.

What is claimed is: 
     
       1. A sheet discharge apparatus comprising:
 a first tray for stacking sheets; and 
 a sheet bundle forming unit that forms a sheet bundle on the first tray, 
 wherein the sheet bundle forming unit forms a first sheet bundle on the first tray, and forms a second sheet bundle stacked on the first sheet bundle in a state wherein the second sheet bundle is offset from the first sheet bundle, the second sheet bundle having a number of sheets that is a same number of the first sheet bundle, 
 when forming each of the first sheet bundle and the second sheet bundle on the first tray, the sheet bundle forming unit divides sheets constituting each of the sheet bundles into a plurality of sets and discharges each of the plurality of sets of sheets individually for each sheet bundle, and 
 one or more sheets included in a first sheet set of the first sheet bundle to be discharged at a first time is set smaller than a number of sheets included in a first sheet set of the second sheet bundle to be discharged at a first time. 
 
     
     
       2. The sheet discharge apparatus according to  claim 1 , wherein the sheet bundle forming unit has a buffer part that temporarily retains conveyed sheets until the number of the conveyed sheets reaches a predetermined number, and a discharge mechanism that discharges the sheets retained in the buffer part onto the first tray. 
     
     
       3. The sheet discharge apparatus according to  claim 2 , further comprising a conveying path for sheet conveyance,
 wherein the buffer part is a second tray for temporarily stacking a sheet conveyed thereto through the conveying path. 
 
     
     
       4. The sheet discharge apparatus according to  claim 2 , further comprising a conveying path for sheet conveyance,
 wherein the buffer part is a diverging path formed so as to diverge from the conveying path. 
 
     
     
       5. The sheet discharge apparatus according to  claim 2 , further comprising a conveying path for sheet conveyance,
 wherein the buffer part is a second tray for temporarily stacking a sheet conveyed thereto through the conveying path, and 
 the discharge mechanism discharges a first sheet of the first sheet bundle conveyed thereto through the conveying path onto the first tray as a sheet divided and discharged for a first time, and discharges a sheet temporarily stacked on the second tray onto the first tray as a second or subsequent sheet. 
 
     
     
       6. The sheet discharge apparatus according to  claim 1 , wherein the plurality of sets forming each of the sheet bundles is stacked to be aligned together. 
     
     
       7. An image forming system comprising:
 an image forming unit that forms an image onto a sheet; 
 a first tray for stacking a sheet on which an image is formed by the image forming unit; and 
 a sheet bundle forming unit that forms a sheet bundle on the first tray, wherein 
 the sheet bundle forming unit forms a first sheet bundle on the first tray, and forms a second sheet bundle stacked on the first sheet bundle in a state wherein the second sheet bundle is offset from the first sheet bundle, the second sheet bundle having a number of sheets that is a same number of the first sheet bundle, 
 when forming each of the first sheet bundle and the second sheet bundle on the first tray, the sheet bundle forming unit divides sheets constituting each of the sheet bundles into a plurality of sets and discharges each of the plurality of sets of sheets individually for each sheet bundle, and 
 one or more sheets included in a first sheet set of the first sheet bundle to be discharged at a first time is set smaller than a number of sheets included in a first sheet set of the second sheet bundle to be discharged at a first time.